%0 Journal Article
%T Investigating Double-Regime Crossover in Y<sub>1</sub>Ba<sub>2</sub>Cu<sub>3 - x</sub>R<sub>x</sub>O<sub>7 - ¦Ä</sub> Superconductors
%A Mohamed H. Badr
%A Lubna M. Sharaf El-Deen
%A Mohamed El-Hofy
%A Aly A. Haswa
%J Crystal Structure Theory and Applications
%P 30-37
%@ 2169-2505
%D 2014
%I Scientific Research Publishing
%R 10.4236/csta.2014.31004
%X <p class=\"MsoNormal\" style=\"text-align:justify;\">
	<span lang=\"EN-US\"><span style=\"font-family:Verdana;\">The effect
of Pr and Gd doping on the transport properties of Cu-deficient YBCO
superconductors has been studied. Two series of Y</span><sub><span style=\"font-family:Verdana;\">1</span></sub><span style=\"font-family:Verdana;\">Ba</span><sub><span style=\"font-family:Verdana;\">2</span></sub><span style=\"font-family:Verdana;\">Cu</span><sub><span style=\"font-family:Verdana;\">3 - </span><i><span style=\"font-family:Verdana;\">x</span></i></sub><span style=\"font-family:Verdana;\">R</span><i><sub><span style=\"font-family:Verdana;\">x</span></sub></i><span style=\"font-family:Verdana;\">O</span><sub><span style=\"font-family:Verdana;\">7 - </span><i><span style=\"font-family:Verdana;\">¦Ä</span></i></sub><span style=\"font-family:Verdana;\">,
where R = Pr or Gd, were prepared by the conventional solid-state reaction
technique. Resistance measurements showed a suppression of T</span><sub><span style=\"font-family:Verdana;\">c</span></sub><span style=\"font-family:Verdana;\"> with
increasing of Pr- and Gd-contents in addition to a normal-state
metal-to-insulator transition. Moreover, a superconductor-to-insulator
transition has been observed at ambient pressure for temperatures less than 50
K for Pr with </span><i><span style=\"font-family:Verdana;\">x</span></i><span style=\"font-family:Verdana;\"> = 0.3 and for Gd with </span><i><span style=\"font-family:Verdana;\">x</span></i><span style=\"font-family:Verdana;\"> &gt; 0.3. The overall complex
behaviours of the resistivity data have been preliminary explained in terms of
localization of charge carriers, structural disorders, and magnetic ordering of
magnetic moments.</span></span> 
</p>
%K High Tc Superconductivity
%K Metal-Insulator Transition
%K Superconductor-Insulator Transition
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=44361